A grain bin cooling control system and method thereof

Abstract

The application discloses a kind of granary cooling control systems, the grain cooling unit has unit air inlet and unit air outlet;The intelligent return air device has first air port, second air port and third air port, first air port is communicated with unit air inlet, second air port is connected with the grain pile return air port of granary by first regulating valve, third air port is connected with the outside of granary by second regulating valve;The intelligent air outlet device has fourth air port, fifth air port and sixth air port, fourth air port is connected with unit air outlet, fifth air port is connected with the grain pile air inlet of granary by third regulating valve, sixth air port is connected with the grain surface air inlet of granary by fourth regulating valve;Compared with prior art, through grain cooling unit, intelligent return air device and intelligent air outlet device, the independent grain pile cooling unit and grain surface cooling unit in prior art can be replaced, equipment integration and one machine multiple use are realized, hardware investment is effectively reduced, and cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of grain storage temperature regulation technology, specifically to a grain storage cooling control system and method. Background Technology

[0002] During the storage of grain in granaries, it is necessary to maintain a low temperature for a long period of time (the temperature inside the granary should not exceed 25°C). The current common practice is to use grain cooling units to cool the inside of the granary when the outdoor temperature is high in summer; when the outdoor temperature is low in winter, air conditioning is not required, and the ventilation equipment inside the granary is manually turned on to mechanically supply air and open the exhaust valves.

[0003] In addition, grain cooling units are divided into grain pile cooling units and grain surface cooling units, the difference of which is:

[0004] The grain pile cooling unit cools the grain pile and is connected to the ground cage air duct of the grain silo. The indoor fan in the grain pile cooling unit is an ultra-high static pressure fan with a long air delivery distance and strong penetration. It is generally turned on periodically and turned off after the grain pile temperature is detected to have reached the set temperature.

[0005] The grain surface cooling unit cools the surface of the grain in the grain silo. The indoor fan of the grain surface cooling unit is a high static pressure fan, which can deliver air over a long distance, but the resistance it needs to overcome is less than that of the grain stacking machine. It is generally kept running for a long time to maintain the grain surface temperature at around the set temperature.

[0006] During use, staff need to manually install the ventilation ducts on the grain pile and grain surface, connect the ducts to the corresponding units, and open the corresponding duct valves according to the actual usage.

[0007] The aforementioned structure for regulating grain silo temperature requires two cooling units, increasing equipment costs. Furthermore, switching the air duct valves requires manual operation, involves numerous steps, requires careful attention, and carries a risk of misoperation. Misoperation could lead to hazards; for example, failure to open the exhaust valve in mechanical ventilation mode could result in excessive positive air pressure inside the silo, potentially damaging the facilities. Summary of the Invention

[0008] In view of the shortcomings of the prior art, the purpose of this invention is to provide a grain silo cooling control system and method to solve the problems of relatively high cost and easy misoperation in the prior art.

[0009] To achieve the above objectives, the first aspect of the present invention adopts the following technical solution: a grain silo cooling control system, comprising:

[0010] A grain cooling unit, wherein the grain cooling unit has an air inlet and an air outlet;

[0011] The intelligent return air device has a first air outlet, a second air outlet and a third air outlet. The first air outlet is connected to the air inlet of the unit. The second air outlet is connected to the return air outlet of the grain pile in the grain silo through a first regulating valve. The third air outlet is connected to the outside of the grain silo through a second regulating valve. The grain silo is equipped with an exhaust valve.

[0012] The intelligent air outlet device has a fourth air outlet, a fifth air outlet and a sixth air outlet. The fourth air outlet is connected to the air outlet of the unit, the fifth air outlet is connected to the air inlet of the grain pile in the grain silo through a third regulating valve, and the sixth air outlet is connected to the air inlet of the grain surface in the grain silo through a fourth regulating valve.

[0013] The controller is connected to the grain cooling unit, the intelligent return air device, the intelligent air outlet device, the first regulating valve, the second regulating valve, the third regulating valve, the fourth regulating valve, and the exhaust valve, and controls the opening and closing of the first regulating valve and the second regulating valve, the third regulating valve and the fourth regulating valve, and the exhaust valve.

[0014] Technical principle:

[0015] This grain warehouse cooling control system has four modes: grain pile cooling mode, grain surface cooling mode, mechanical ventilation mode, and internal circulation mode.

[0016] When in grain pile cooling mode, the controller closes the second regulating valve, the fourth regulating valve and the exhaust valve and opens the first regulating valve and the third regulating valve. At the same time, the grain cooling unit operates to create a cold cycle between the intelligent return air device, the grain cooling unit, the intelligent exhaust air device and the grain pile in the grain silo, so as to adjust the grain pile temperature to and maintain it within the preset grain pile temperature threshold range.

[0017] When the grain surface cooling mode is in operation, the controller closes the second regulating valve, the third regulating valve and the exhaust valve and opens the first regulating valve and the fourth regulating valve. At the same time, the grain cooling unit operates to create a cold cycle between the intelligent return air device, the grain cooling unit, the intelligent exhaust air device and the grain pile in the grain silo, so as to adjust the grain pile temperature to and maintain it within the preset grain pile temperature threshold range.

[0018] In mechanical ventilation mode, the controller closes the first and fourth regulating valves and opens the second, third, and exhaust valves. At the same time, the grain cooling unit only operates for ventilation and does not cool, thus creating a ventilation channel between the outside air environment, the intelligent return air device, the grain cooling unit, the intelligent exhaust device, and the grain pile inside the grain silo to balance the temperature inside and outside the grain silo.

[0019] In internal circulation mode, the controller closes the second regulating valve, the third regulating valve, and the exhaust valve, and opens the first regulating valve and the fourth regulating valve. At the same time, the grain cooling unit only operates ventilation and does not cool, so as to form an internal circulation between the intelligent return air device, the grain cooling unit, the intelligent exhaust air device, and the grain pile in the grain silo, so as to circulate the cold air in the grain pile to the grain surface.

[0020] Furthermore, a dehumidification module is installed inside the first air vent, and the dehumidification module includes:

[0021] The box body is disposed inside the first air vent and forms a conduction channel with the first air vent. The box body has an air inlet guide opening facing the air inlet side of the first air vent and an air outlet guide opening facing the air outlet side of the first air vent. Both the air inlet guide opening and the air outlet guide opening are provided with a cover plate connected to the controller.

[0022] A filter screen is disposed inside the housing and located between the air inlet and the air outlet.

[0023] A desiccant is filled inside the housing and located between the filter and the air outlet.

[0024] Furthermore, the grain cooling unit includes:

[0025] The housing has an air inlet and an air outlet for the unit.

[0026] The refrigeration unit is located inside the casing and is a vapor compression refrigeration cycle system.

[0027] Furthermore, a humidifier is installed inside the casing, located between the internal fan and the evaporator of the vapor compression refrigeration cycle system.

[0028] Furthermore, the humidifier is connected to the water receiving tray of the evaporator.

[0029] The second aspect of this invention adopts the following technical solution: a grain silo cooling control method, based on the grain silo cooling control system described in the first aspect of this invention, comprising the following steps:

[0030] Upon initial power-on, the system responds to the user's startup request and enters the working state.

[0031] Obtain the system's mode selection command, which is either a target operating mode manually specified by the user or a command to trigger the system to automatically select the operating mode;

[0032] The current operating mode is determined according to the mode selection instruction; wherein, the mode selection instruction is an instruction that triggers the system to automatically select the operating mode, and the system automatically determines the operating mode based on the detected outdoor ambient temperature.

[0033] According to the determined operating mode, the operating status of each component in the grain cooling unit is controlled, and at least one of the following is regulated by controlling the opening and closing of the first to fourth regulating valves and the exhaust valve: grain pile temperature, grain surface temperature, ventilation status and humidity inside the grain silo; wherein, the operating mode includes grain pile cooling mode, grain surface cooling mode, mechanical ventilation mode and internal circulation mode.

[0034] Furthermore, when the device is shut down and restarted without a power outage, the default operating mode is the final operating mode that was running before the last shutdown.

[0035] Furthermore, the grain pile cooling mode includes adjusting the temperature of the grain pile, the specific operation of which is as follows:

[0036] In response to the command to activate the grain pile cooling mode, the following steps are executed:

[0037] Close the second regulating valve, the fourth regulating valve, and the exhaust valve, and open the first regulating valve and the third regulating valve;

[0038] Simultaneously start the internal fan, compressor and external fan of the grain cooling unit, and set the internal fan to operate at the set maximum wind speed;

[0039] The return air temperature inside the grain silo and the evaporator coil temperature of the grain cooling unit are obtained.

[0040] Based on the return air temperature inside the warehouse, the evaporator coil temperature, and the expression relating temperature and wind speed, the wind speed of the internal fan is dynamically adjusted to ensure that the grain pile temperature reaches and is maintained within the preset grain pile temperature threshold range.

[0041] Furthermore, the internal fan is a DC fan or an AC fan;

[0042] When the internal fan is a DC fan, the expression for the relationship between temperature and wind speed is:

[0043] ;

[0044]

[0045] ;

[0046] ;

[0047] ;

[0048] Among them, the The adjusted airflow speed of the internal fan. This refers to the current airflow speed of the internal fan; The temperature inside the warehouse; This refers to the temperature of the evaporator coil. For the target temperature difference, The current calculated value of A. The A value calculated for the previous testing cycle;

[0049] When the internal fan is an AC fan, the wind speed relationship expression is:

[0050]

[0051] ;

[0052] Among them, the The adjusted airflow speed of the internal fan. This refers to the current airflow speed of the internal fan; The temperature inside the warehouse; This refers to the temperature of the evaporator coil. For the target temperature difference, The current calculated value of A. The A value is calculated for the previous testing cycle.

[0053] Furthermore, the grain pile cooling mode also includes humidity control within the storage area, the specific operation of which is as follows:

[0054] In response to the start command of the grain pile cooling mode, the humidity inside the warehouse is obtained;

[0055] Humidification, dehumidification, or no humidity treatment is performed based on the obtained humidity inside the warehouse and the preset humidity threshold until the humidity inside the warehouse reaches and is maintained within the preset humidity threshold range.

[0056] Specifically, the humidification process includes:

[0057] In response to the humidification signal, the humidifier in the grain cooling unit is activated;

[0058] During the humidification process, the fan speed of the internal fan is adjusted to the set maximum value, and the operating frequency of the compressor is gradually reduced at intervals of each detection cycle.

[0059] Continue humidification and frequency adjustment until the frequency adjustment stops when any of the following conditions are met:

[0060] (1) The current detected evaporator coil temperature is higher than the dew point temperature determined based on the relative humidity collected in the chamber in the previous detection cycle;

[0061] (2) The operating frequency of the compressor has been reduced to the set minimum value;

[0062] The dehumidification process specifically includes:

[0063] In response to the dehumidification signal, the dehumidification module is activated;

[0064] Get the current airflow speed of the internal fan;

[0065] Based on the obtained current internal fan speed and the minimum set internal fan speed, the internal fan speed is adjusted to the set minimum value or zero for operation.

[0066] Furthermore, the dew point temperature corresponding to the relative humidity is calculated according to the following formula:

[0067]

[0068] Wherein, Td is the dew point temperature (°C); Ta is the return air temperature inside the warehouse (°C); RH is the relative humidity; A and B are both empirical coefficients, and A=17.625, B=243.04.

[0069] Furthermore, the grain surface cooling mode includes the regulation of grain pile temperature and humidity inside the storage area. The specific operation for regulating the grain pile temperature is as follows:

[0070] In response to the start command for the grain surface cooling mode, the following steps are executed:

[0071] Close the second regulating valve, the third regulating valve, and the exhaust valve, and open the first regulating valve and the fourth regulating valve;

[0072] Simultaneously start the internal fan, compressor and external fan in the grain cooling unit, and set the internal fan to operate at the set maximum wind speed;

[0073] The return air temperature inside the grain silo and the evaporator coil temperature of the grain cooling unit are obtained.

[0074] The wind speed of the internal fan is dynamically adjusted based on the return air temperature inside the warehouse and the evaporator coil temperature, so that the grain surface temperature reaches and is maintained within the preset grain surface temperature threshold.

[0075] Furthermore, the mechanical ventilation mode includes adjusting the ventilation status, specifically as follows:

[0076] In response to the command to activate mechanical ventilation mode, the following steps are performed:

[0077] Close the first and fourth regulating valves, and open the second, third, and exhaust valves;

[0078] At the same time, the internal fan in the grain cooling unit is started to operate at the set maximum wind speed or the wind speed value input by the user.

[0079] Furthermore, the mechanical ventilation mode also includes humidity control within the warehouse, the specific operation of which is as follows:

[0080] The humidity inside the chamber is obtained in response to the start command of the mechanical ventilation mode;

[0081] Humidification, dehumidification, or no humidity treatment is performed based on the obtained humidity inside the chamber and the preset humidity threshold until the humidity inside the chamber reaches and is maintained within the preset humidity threshold range.

[0082] Furthermore, the internal circulation mode includes the adjustment of the ventilation state, the specific operation of which is as follows:

[0083] In response to the start command for the grain surface cooling mode, the following steps are executed:

[0084] Close the second regulating valve, the third regulating valve, and the exhaust valve, and open the first regulating valve and the fourth regulating valve;

[0085] At the same time, the internal fan in the grain cooling unit is started to operate at the set maximum wind speed or the wind speed value input by the user.

[0086] Compared with the prior art, the present invention has the following beneficial effects:

[0087] 1. By using grain cooling units, intelligent return air devices, and intelligent air outlet devices, the existing separate grain pile cooling units and grain surface cooling units can be replaced, realizing equipment integration and multi-purpose use, effectively reducing hardware investment and lowering costs.

[0088] 2. The controller automatically selects and switches between four operating modes—grain pile cooling, grain surface cooling, mechanical ventilation, and internal circulation—based on ambient temperature or commands, and controls all regulating valves and unit operating status in a coordinated manner. This completely avoids the cumbersome, omission, or error problems that may result from manually switching air ducts and opening and closing valves, greatly improving the safety and reliability of the system operation.

[0089] 3. The system can intelligently match the optimal operating mode. For example, in winter or when the outdoor temperature is suitable, it automatically adopts the "mechanical ventilation mode" that only ventilates and does not cool, making full use of natural cold sources to cool down and significantly reducing energy consumption; when it is necessary to balance the temperature of the grain pile and the grain surface, the "internal circulation mode" is adopted to realize the recycling of cold energy in the warehouse, avoiding unnecessary cooling starts, thereby improving overall energy efficiency and reducing the operating cost of long-term grain storage.

[0090] 4. For different modes (such as cooling of grain piles / grain surfaces) and specific treatments (such as humidification), the system can dynamically adjust parameters such as internal fan speed and compressor frequency, and perform closed-loop regulation in conjunction with real-time temperature, humidity, and dew point temperature. This precise control ensures that the temperature of the grain pile and grain surface can be quickly and stably maintained within the set threshold, and effectively prevents quality problems such as grain condensation caused by excessive cooling or improper humidity management, thus ensuring the safety and quality of stored grain.

[0091] 5. The system has adaptive mode selection logic (such as judging based on outdoor temperature) and state memory function (restoring the last mode after a power outage and restart), which enables the system to flexibly respond to the grain storage needs under different seasons and climate conditions, reduce manual intervention, and realize intelligent and continuous grain storage environment management. Attached Figure Description

[0092] Figure 1 This is a process flow diagram of an embodiment of the present invention;

[0093] Figure 2 This is a process flow diagram of a vapor compression refrigeration cycle system according to an embodiment of the present invention;

[0094] Figure 3 This is a partial structural diagram of a grain cooling unit in one embodiment of the present invention;

[0095] Figure 4 for Figure 3 Diagram showing the connection between the water tray and the humidifier;

[0096] Figure 5 for Figure 4 A schematic diagram of the structure of a medium-sized humidifier;

[0097] Figure 6 This is a schematic diagram of the structure of the wet module in the off state according to an embodiment of the present invention;

[0098] Figure 7 This is a partial schematic diagram of the wet module in one embodiment of the present invention.

[0099] The reference numerals in the accompanying drawings include:

[0100] Grain cooling unit 1, unit air inlet 11, unit air outlet 12, evaporator 13, water receiving tray 131, gas-liquid separator 14, compressor 15, condenser 16, throttling element 17, internal fan 18, external fan 19, humidifier 110, liquid inlet pipe 11a, overflow pipe 11b, intelligent return air device 2, first air outlet 21, second air outlet 22, third air outlet 23, intelligent air outlet device 3, fourth air outlet 31, fifth air outlet 32, sixth air outlet 33, grain bin 4, grain pile return air outlet 41, grain pile air inlet 42, grain surface air inlet 43, exhaust valve 44, dehumidification module 5, box 51, filter screen 52, desiccant 53, cover plate 54. Detailed Implementation

[0101] The present invention will be further described in detail below through specific embodiments:

[0102] like Figure 1 As shown, an embodiment of the present invention provides a grain silo cooling control system, including a grain cooling unit 1, an intelligent return air device 2, an intelligent air outlet device 3, and a controller. The grain cooling unit 1 has a unit air inlet 11 and a unit air outlet 12; the intelligent return air device 2 has a first air outlet 21, a second air outlet 22, and a third air outlet 23. The first air outlet 21 is connected to the unit air inlet 11, the second air outlet 22 is connected to the grain pile return air outlet 41 of the grain silo 4 through a first regulating valve, and the third air outlet 23 is connected to the outside of the grain silo 4 through a second regulating valve. The grain silo 4 is equipped with an exhaust valve 44; the intelligent air outlet device 3 has... The fourth air outlet 31, the fifth air outlet 32, and the sixth air outlet 33 are connected. The fourth air outlet 31 is connected to the air outlet 12 of the unit. The fifth air outlet 32 ​​is connected to the air inlet 42 of the grain pile of the grain silo 4 through the third regulating valve. The sixth air outlet 33 is connected to the air inlet 43 of the grain surface of the grain silo 4 through the fourth regulating valve. The controller is connected to the grain cooling unit 1, the intelligent return air device 2, the intelligent air outlet device 3, the first regulating valve, the second regulating valve, the third regulating valve, the fourth regulating valve, and the exhaust valve 44. The controller controls the opening and closing of the first regulating valve and the second regulating valve, the opening of the third regulating valve and the fourth regulating valve, and the opening and closing of the exhaust valve 44.

[0103] Technical principle:

[0104] This grain warehouse cooling control system has four modes: grain pile cooling mode, grain surface cooling mode, mechanical ventilation mode, and internal circulation mode.

[0105] When in grain pile cooling mode, the controller closes the second regulating valve, the fourth regulating valve and the exhaust valve 44 and opens the first regulating valve and the third regulating valve. At the same time, the grain cooling unit 1 operates to cool, forming a cold cycle between the intelligent return air device 2, the grain cooling unit 1, the intelligent exhaust air device 3 and the grain pile in the grain silo 4, so as to adjust the grain pile temperature to and maintain it within the preset grain pile temperature threshold range.

[0106] When the grain surface cooling mode is in operation, the controller closes the second regulating valve, the third regulating valve and the exhaust valve 44 and opens the first regulating valve and the fourth regulating valve. At the same time, the grain cooling unit 1 operates to cool the grain, forming a cold cycle between the intelligent return air device 2, the grain cooling unit 1, the intelligent exhaust air device 3 and the grain pile in the grain silo 4, so as to adjust and maintain the grain pile temperature within the preset grain pile temperature threshold range.

[0107] In mechanical ventilation mode, the controller closes the first and fourth regulating valves and opens the second and third regulating valves and the exhaust valve 44. At the same time, the grain cooling unit 1 only operates ventilation and does not cool, so as to create a ventilation channel between the outside air environment, the intelligent return air device 2, the grain cooling unit 1, the intelligent exhaust air device 3 and the grain pile in the grain silo 4, so as to balance the temperature inside and outside the grain silo 4.

[0108] In the internal circulation mode, the controller closes the second regulating valve, the third regulating valve, and the exhaust valve 44 and opens the first regulating valve and the fourth regulating valve. At the same time, the grain cooling unit 1 only operates ventilation and does not cool, so as to form an internal circulation between the intelligent return air device 2, the grain cooling unit 1, the intelligent exhaust air device 3, and the grain pile in the grain bin 4, so as to circulate the cold air in the grain pile to the grain surface.

[0109] In this embodiment, the intelligent return air device 2 is specifically a return air box. The side wall of the return air box has a first air vent 21, a second air vent 22 and a third air vent 23. A filter screen 52 can be placed in front of the first air vent 21.

[0110] The intelligent air outlet device 3 is specifically an air outlet box, and the fourth air outlet 31, the fifth air outlet 32 ​​and the sixth air outlet 33 are opened on the side wall of the air outlet box.

[0111] The grain cooling unit 1 includes a casing, a refrigeration unit, and a control unit connected to the refrigeration unit. The casing has an air inlet 11 and an air outlet 12. The refrigeration unit is located inside the casing and is a vapor compression refrigeration cycle system. The control unit can be the controller.

[0112] Among them, such as Figure 2 As shown, the vapor compression refrigeration cycle system is an existing system, specifically including an evaporator 13, a gas-liquid separator 14, a compressor 15, a condenser 16, and a throttling element 17 connected in sequence. The evaporator 13 is equipped with an internal fan 18, and the condenser 16 is equipped with an external fan 19.

[0113] Excessive humidity can easily cause grains to mold and sprout, while excessively low humidity can lead to severe dehydration. Therefore, humidity control is necessary during grain storage. This system can regulate not only the temperature in grain pile cooling mode, grain surface cooling mode, and mechanical ventilation mode, but also the humidity inside the storage area.

[0114] In this system, such as Figures 3-5 As shown, a humidifier 110 is installed inside the casing, located between the internal fan 18 and the evaporator 13 of the vapor compression refrigeration cycle system. When the humidity inside the grain silo 4 is detected to be too low, the controller drives the humidifier 110 to operate. Under the action of the internal fan 18 and the evaporator 13, the atomized water vapor generated by the humidifier 110 is delivered to the grain silo 4 for humidification. The humidifier 110 has a liquid inlet pipe 11a at its bottom connected to a water receiving tray 131 to form a communicating vessel. The top of the humidifier 110 is equipped with an air outlet pipe. An electric heating rod inside the humidifier 110 heats the water to generate steam, which is discharged from the air outlet pipe. The water receiving tray 131 collects the condensate generated by the evaporator 13 and then introduces it into the humidifier 110 for replenishment. The humidifier 110 is also equipped with an overflow pipe 11b connected to the water receiving tray 131. The overflow pipe 11b guides excess water in the humidifier 110 back to the water receiving tray 131.

[0115] It should be noted that the humidifier 110 is also provided with an external liquid inlet.

[0116] Furthermore, in this system, such as Figure 6 and Figure 7 As shown, a dehumidification module 5 is provided inside the first air vent 21. The dehumidification module 5 includes a housing 51, a filter screen 52, and a desiccant 53. The housing 51 is disposed inside the first air vent 21 and forms a conductive channel with the housing 51. The housing 51 has an air inlet facing the air inlet side of the first air vent 21 and an air outlet facing the air outlet side of the first air vent 21. Both the air inlet and air outlet are provided with a cover plate 54 connected to the controller. The filter screen 52 is disposed inside the housing 51 and located between the air inlet and air outlet. The desiccant 53 is filled inside the housing 51 and located between the filter screen 52 and the air outlet.

[0117] When the humidity inside the grain silo 4 is suitable and dehumidification is not required, both the air inlet and outlet are sealed by the corresponding covers 54. At this time, the airflow passing through the first air vent 21 flows out through the channel. When the humidity inside the grain silo 4 is detected to be too high, the controller drives the two covers 54 to open, opening both the air inlet and outlet. At this time, part of the airflow passing through the first air vent 21 flows out through the channel, and part enters the box 51 through the air inlet, is filtered by the filter screen 52, and then passes through the desiccant 53 to absorb water for dehumidification. Finally, it is discharged from the air outlet and mixed before entering the grain silo 4 to dehumidify the grain silo 4.

[0118] In the above, the cover plate 54 can be driven to open and close by an existing electric control structure. The controller is connected to the electric control structure, and the controller controls the electric control structure to drive the cover plate 54 to open and close.

[0119] The hygroscopic agent 53 is a molecular sieve or quicklime, etc.

[0120] Based on the above-mentioned grain silo cooling control system, another embodiment of the present invention also proposes a grain silo cooling control method, including the following steps:

[0121] Upon initial power-on, the system responds to the user's startup operation and enters the working state. It acquires the system's mode selection command, which can be either a user-manually specified target operating mode or a command to trigger the system to automatically select an operating mode. Based on the mode selection command, the system determines the current operating mode. If the mode selection command triggers the system to automatically select an operating mode, the system automatically determines the operating mode based on the detected outdoor ambient temperature. According to the determined operating mode, the system controls the operating status of each component in the grain cooling unit 1 and adjusts at least one of the following in the grain silo 4: grain pile temperature, grain surface temperature, ventilation status, and humidity, by controlling the opening and closing of the first to fourth regulating valves and the exhaust valve 44. The operating modes include grain pile cooling mode, grain surface cooling mode, mechanical ventilation mode, and internal circulation mode. Furthermore, when the system is restarted after being shut down in a non-power-off state, the default operating mode is the final operating mode used before the last shutdown.

[0122] The specific steps are as follows:

[0123] After the system is powered on for the first time, it can be started and operated via the intelligent wired controller, and the system will enter the working state. At this time, if the user directly selects any of the following modes—grain pile cooling mode, grain surface cooling mode, mechanical ventilation mode, or internal circulation mode—using the mode selection button on the intelligent wired controller, the system will operate according to the selected mode. If the user does not select an operating mode within a preset time period (e.g., 1 minute), the system will be triggered to automatically select an operating mode. First, it needs to obtain the outdoor ambient temperature, then automatically select the operating mode based on the obtained outdoor ambient temperature, and finally start the grain cooling unit 1.

[0124] The logic for automatically selecting the operating mode is as follows: when the outdoor ambient temperature is >26℃, the grain pile cooling mode is selected; when the outdoor ambient temperature is 15℃≤26℃, the grain surface cooling mode is selected; and when the outdoor ambient temperature is <15℃, the mechanical ventilation mode is selected.

[0125] The four operating modes mentioned above are described below:

[0126] 1. Grain pile cooling mode

[0127] The grain pile cooling mode includes adjusting the temperature of the grain pile, and its specific operation is as follows:

[0128] In response to the start command of the grain pile cooling mode, the following steps are performed: close the second regulating valve, the fourth regulating valve and the exhaust valve 44, and open the first regulating valve and the third regulating valve; simultaneously start the internal fan 18, the compressor 15 and the external fan 19 of the grain cooling unit 1, and set the internal fan 18 to operate at the set maximum wind speed; obtain the return air temperature inside the grain silo 4 and the coil temperature of the evaporator 13 of the grain cooling unit 1;

[0129] Based on the return air temperature inside the warehouse, the coil temperature of the evaporator 13, and the expression relating temperature and wind speed, the wind speed of the internal fan 18 is dynamically adjusted so that the grain pile temperature reaches and is maintained within the preset grain pile temperature threshold range.

[0130] The internal fan 18 is a DC fan or an AC fan;

[0131] When the internal fan 18 is a DC fan, the expression for the relationship between temperature and wind speed is:

[0132] ;

[0133] ;

[0134] ;

[0135] ;

[0136] ;

[0137] Among them, the The adjusted airflow speed of the internal fan. This refers to the current airflow speed of the internal fan; The temperature inside the warehouse; This refers to the temperature of the evaporator coil. For the target temperature difference, The current calculated value of A. The A value calculated for the previous testing cycle;

[0138] When the internal fan is an AC fan, the wind speed relationship expression is:

[0139]

[0140] ;

[0141] Among them, the The adjusted airflow speed of the internal fan. This refers to the current airflow speed of the internal fan; The temperature inside the warehouse; This refers to the temperature of the evaporator coil. For the target temperature difference, The current calculated value of A. The A value is calculated for the previous testing cycle.

[0142] It should be noted that the set maximum and minimum speeds vary depending on the type of fan selected by the manufacturer. The maximum and minimum speeds refer to the highest and lowest operating speeds the fan can achieve during normal operation. For example, for an AC motor, a 3-speed setting corresponds to maximum / medium / minimum speeds of 850 RPM / 650 RPM / 350 RPM respectively. For an EC DC motor, the speed range is 350 RPM to 1200 RPM, with a maximum speed of 1200 RPM and a minimum speed of 350 RPM.

[0143] Specifically, when the judgment is true and the internal fan 18 is at its highest speed, the gear of the internal fan 18 remains unchanged, and the internal fan 18 continues to operate at its highest speed; when the judgment is false and the internal fan 18 is at its lowest speed, the gear of the internal fan 18 remains unchanged, and the internal fan 18 continues to operate at its lowest speed.

[0144] The specific temperature threshold for the grain pile is set to 10~26℃, with a default value of 16℃.

[0145] The grain pile cooling mode also includes humidity control inside the storage area, the specific operation of which is as follows:

[0146] In response to the start command of the grain pile cooling mode, the humidity inside the warehouse is obtained; based on the obtained humidity inside the warehouse and the preset humidity threshold, humidification, dehumidification or no humidity treatment is performed until the humidity inside the warehouse reaches and is maintained within the preset humidity threshold range.

[0147] In the above, the preset humidity threshold is set to [Kc, K+c]. When the detected humidity RH in the warehouse is less than Kc, humidification is performed; when the humidity in the warehouse is within the range of [Kc, K+c], no humidity treatment is performed; when the humidity in the warehouse is greater than K+c, dehumidification is performed.

[0148] Specifically, the humidification process includes:

[0149] In response to the humidification signal, the humidifier 110 in the grain cooling unit 1 is activated; during humidification, the air speed of the internal fan 18 is adjusted to the set maximum value, and the operating frequency of the compressor 15 is gradually reduced at intervals of each detection cycle (for example, each detection cycle is 30 seconds, and the reduction in the operating frequency of the compressor 15 in each detection cycle is 0.5 rpm); the humidification and operating frequency adjustment are continuously performed until the operating frequency adjustment stops when any of the following conditions are met:

[0150] (1) The current detected temperature of the evaporator coil 13 is higher than the dew point temperature determined based on the relative humidity collected in the chamber in the previous detection cycle.

[0151] (2) The operating frequency of the compressor 15 has been reduced to the set minimum value (generally 30Hz).

[0152] During the humidification process, the humidifier 110 stops working once the humidity inside the warehouse reaches the K value. The internal fan 18 and compressor 15 resume operation 1 minute later in accordance with the adjustment of the grain pile temperature.

[0153] The dew point temperature corresponding to the relative humidity is calculated according to the following formula:

[0154]

[0155] Wherein, Td is the dew point temperature (°C); Ta is the return air temperature inside the warehouse (°C); RH is the relative humidity; A and B are both empirical coefficients, and A=17.625, B=243.04.

[0156] The dehumidification process specifically includes:

[0157] In response to the dehumidification signal, the dehumidification module 5 is started; the current wind speed of the indoor fan 18 is obtained; and the wind speed of the indoor fan 18 is adjusted to the set minimum value or zero according to the obtained current wind speed of the indoor fan 18 and the set minimum value of the wind speed of the indoor fan 18.

[0158] If the internal fan 18 is operating at a speed other than the minimum during normal operation, the speed of the internal fan 18 will be reduced to the minimum value; if the speed of the internal fan 18 is already at the minimum value during normal operation, the internal fan 18 will stop operating. During the dehumidification process, the dehumidification module 5 will stop working once the humidity inside the silo reaches the K value, and the internal fan 18 and compressor 15 will resume operation after 1 minute in accordance with the adjustment of the grain pile temperature.

[0159] 2. Grain and Surface Cooling Mode

[0160] The grain surface cooling mode includes the adjustment of the grain pile temperature, and its specific operation is as follows:

[0161] In response to the start command for the grain surface cooling mode, the following steps are executed:

[0162] Close the second regulating valve, the third regulating valve, and the exhaust valve 44, and open the first regulating valve and the fourth regulating valve; simultaneously start the internal fan 18, the compressor 15, and the external fan 19 in the grain cooling unit 1, and set the internal fan 18 to operate at the set maximum wind speed; obtain the return air temperature inside the grain silo 4 and the coil temperature of the evaporator 13 of the grain cooling unit 1; dynamically adjust the wind speed of the internal fan 18 according to the return air temperature inside the silo and the coil temperature of the evaporator 13, so that the grain surface temperature reaches and is maintained within the preset grain surface temperature threshold.

[0163] Here, the preset grain surface temperature threshold is 10~26℃, and its default value is 12℃. Furthermore, in the grain pile cooling mode, the process of dynamically adjusting the wind speed of the internal fan 18 based on the return air temperature inside the storage silo and the coil temperature of the evaporator 13 to ensure that the grain surface temperature reaches and is maintained within the preset grain surface temperature threshold has the same control process as in the grain pile cooling mode, and will not be described again here.

[0164] The grain surface cooling mode also includes the regulation of humidity inside the warehouse. In this mode, the process of regulating humidity inside the warehouse has the same control process as that in the grain pile cooling mode, and will not be described again here.

[0165] 3. Mechanical ventilation mode

[0166] The mechanical ventilation mode includes adjusting the ventilation status, the specific operation of which is as follows:

[0167] In response to the start command for mechanical ventilation mode, the following steps are performed: the first and fourth regulating valves are closed, and the second, third, and exhaust valves 44 are opened; simultaneously, the internal fan 18 in the grain cooler unit 1 is started to operate at the set maximum airflow speed or the user-input airflow speed value. In this mode, the compressor 15 and the external fan 19 in the grain cooler unit 1 are not started.

[0168] The mechanical ventilation mode also includes humidity control within the warehouse, the specific operation of which is as follows:

[0169] In response to the start command of mechanical ventilation mode, the humidity inside the chamber is acquired; based on the acquired humidity inside the chamber and a preset humidity threshold, humidification, dehumidification, or no humidity treatment is performed until the humidity inside the chamber reaches and is maintained within the preset humidity threshold range.

[0170] For example, the user sets a target humidity value K and a positive / negative deviation range c, i.e., the preset humidity threshold range is [Kc, K+c]. When the humidity RH inside the chamber is detected to be less than Kc, humidification is initiated. Humidifier 110 stops working once the humidity inside the chamber reaches the K value. When the humidity inside the chamber is detected to be greater than k+c, a separate dehumidification module 5 is activated, and it stops working once the humidity reaches the K value.

[0171] 4. Internal circulation mode

[0172] The internal circulation mode includes the adjustment of the ventilation state, the specific operation of which is as follows:

[0173] In response to the start command of the grain surface cooling mode, the following steps are performed: the second regulating valve, the third regulating valve, and the exhaust valve 44 are closed, and the first regulating valve and the fourth regulating valve are opened; simultaneously, the internal fan 18 in the grain cooling unit 1 is started to operate at the set maximum wind speed or the wind speed value input by the user. In this mode, the compressor 15 and the external fan 19 are not started; this mode is mainly suitable for the transition period between natural ventilation and forced cooling, and can circulate the cold air in the grain pile to the grain surface.

[0174] It should be noted that:

[0175] The temperature or humidity obtained through detection is obtained by temperature or humidity sensors installed at the corresponding locations in this system. The controller of this system is an existing CPU, which can also record the system's power-on time, power-off time, operating mode, single operation time, internal temperature, single operation energy consumption, and cumulative power consumption. It can also automatically generate single operation energy consumption curves, air supply temperature during operation, and internal temperature curves, and historical records can be checked.

[0176] This system has the following technical advantages:

[0177] 1. By using the grain cooling unit 1, intelligent return air device 2 and intelligent air outlet device 3, the existing separate grain pile cooling unit and grain surface cooling unit can be replaced, realizing equipment integration and multi-purpose use, effectively reducing hardware investment and lowering costs.

[0178] 2. The controller automatically selects and switches between four operating modes—grain pile cooling, grain surface cooling, mechanical ventilation, and internal circulation—based on ambient temperature or commands, and controls all regulating valves and unit operating status in a coordinated manner. This completely avoids the cumbersome, omission, or error problems that may result from manually switching air ducts and opening and closing valves, greatly improving the safety and reliability of the system operation.

[0179] 3. The system can intelligently match the optimal operating mode. For example, in winter or when the outdoor temperature is suitable, it automatically adopts the "mechanical ventilation mode" that only ventilates and does not cool, making full use of natural cold sources to cool down and significantly reducing energy consumption; when it is necessary to balance the temperature of the grain pile and the grain surface, the "internal circulation mode" is adopted to realize the recycling of cold energy in the warehouse, avoiding unnecessary cooling starts, thereby improving overall energy efficiency and reducing the operating cost of long-term grain storage.

[0180] 4. For different modes (such as cooling of grain piles / grain surfaces) and specific treatments (such as humidification), the system can dynamically adjust parameters such as the internal fan speed (18) and compressor frequency (15), and perform closed-loop regulation in conjunction with real-time temperature, humidity, and dew point temperature. This refined control ensures that the temperature of the grain pile and grain surface can be quickly and stably maintained within the set threshold, and effectively prevents quality problems such as grain condensation caused by excessive cooling or improper humidity management, thus ensuring the safety and quality of stored grain.

[0181] 5. The system has adaptive mode selection logic (such as judging based on outdoor temperature) and state memory function (restoring the last mode after a power outage and restart), which enables the system to flexibly respond to the grain storage needs under different seasons and climate conditions, reduce manual intervention, and realize intelligent and continuous grain storage environment management.

[0182] 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 silo cooling control system, characterized in that, include: A grain cooling unit, wherein the grain cooling unit has an air inlet and an air outlet; The intelligent return air device has a first air outlet, a second air outlet and a third air outlet. The first air outlet is connected to the air inlet of the unit. The second air outlet is connected to the return air outlet of the grain pile in the grain silo through a first regulating valve. The third air outlet is connected to the outside of the grain silo through a second regulating valve. The grain silo is equipped with an exhaust valve. The intelligent air outlet device has a fourth air outlet, a fifth air outlet and a sixth air outlet. The fourth air outlet is connected to the air outlet of the unit, the fifth air outlet is connected to the air inlet of the grain pile in the grain silo through a third regulating valve, and the sixth air outlet is connected to the air inlet of the grain surface in the grain silo through a fourth regulating valve. The controller is connected to the grain cooling unit, the intelligent return air device, the intelligent air outlet device, the first regulating valve, the second regulating valve, the third regulating valve, the fourth regulating valve, and the exhaust valve, and controls the opening and closing of the first regulating valve and the second regulating valve, the third regulating valve and the fourth regulating valve, and the exhaust valve.

2. The grain silo cooling control system according to claim 1, characterized in that, The first air vent is equipped with a dehumidification module, which includes: The box body is disposed inside the first air vent and forms a conduction channel with the first air vent. The box body has an air inlet guide opening facing the air inlet side of the first air vent and an air outlet guide opening facing the air outlet side of the first air vent. Both the air inlet guide opening and the air outlet guide opening are provided with a cover plate connected to the controller. A filter screen is disposed inside the housing and located between the air inlet and the air outlet. A desiccant is filled inside the housing and located between the filter and the air outlet.

3. The grain silo cooling control system according to claim 1, characterized in that, The grain cooling unit includes: The housing has an air inlet and an air outlet for the unit. The refrigeration unit is located inside the casing and is a vapor compression refrigeration cycle system.

4. A grain silo cooling control system according to claim 3, characterized in that, The casing contains a humidifier located between the internal fan and the evaporator in the vapor compression refrigeration cycle system.

5. A grain silo cooling control system according to claim 4, characterized in that, The humidifier is connected to the water receiving tray of the evaporator.

6. A method for controlling cooling in a grain silo, characterized in that, A grain storage cooling control system based on any one of claims 1-5 includes the following steps: Upon initial power-on, the system responds to the user's startup request and enters the working state. Obtain the system's mode selection command, which is either a target operating mode manually specified by the user or a command to trigger the system to automatically select the operating mode; The current operating mode is determined according to the mode selection instruction; wherein, the mode selection instruction is an instruction that triggers the system to automatically select the operating mode, and the system automatically determines the operating mode based on the detected outdoor ambient temperature. According to the determined operating mode, the operating status of each component in the grain cooling unit is controlled, and at least one of the following is regulated by controlling the opening and closing of the first to fourth regulating valves and the exhaust valve: grain pile temperature, grain surface temperature, ventilation status and humidity inside the grain silo; wherein, the operating mode includes grain pile cooling mode, grain surface cooling mode, mechanical ventilation mode and internal circulation mode. Furthermore, when the device is shut down and restarted without a power outage, the default operating mode is the final operating mode that was running before the last shutdown.

7. The grain silo cooling control method according to claim 6, characterized in that, The grain pile cooling mode includes adjusting the temperature of the grain pile, and its specific operation is as follows: In response to the command to activate the grain pile cooling mode, the following steps are executed: Close the second regulating valve, the fourth regulating valve, and the exhaust valve, and open the first regulating valve and the third regulating valve; Simultaneously start the internal fan, compressor and external fan of the grain cooling unit, and set the internal fan to operate at the set maximum wind speed; The return air temperature inside the grain silo and the evaporator coil temperature of the grain cooling unit are obtained. Based on the return air temperature inside the warehouse, the evaporator coil temperature, and the expression relating temperature and wind speed, the wind speed of the internal fan is dynamically adjusted to ensure that the grain pile temperature reaches and is maintained within the preset grain pile temperature threshold range.

8. The grain silo cooling control method according to claim 7, characterized in that, The internal fan is a DC fan or an AC fan; When the internal fan is a DC fan, the expression for the relationship between temperature and wind speed is: ； ； ； ； ； Among them, the The adjusted airflow speed of the internal fan. This refers to the current airflow speed of the internal fan; The temperature inside the warehouse; This refers to the temperature of the evaporator coil. For the target temperature difference, The current calculated value of A. The A value calculated for the previous testing cycle; When the internal fan is an AC fan, the wind speed relationship expression is: ； Among them, the The adjusted airflow speed of the internal fan. This refers to the current airflow speed of the internal fan; The temperature inside the warehouse; This refers to the temperature of the evaporator coil. For the target temperature difference, The current calculated value of A. The A value is calculated for the previous testing cycle.

9. A grain silo cooling control method according to claim 7 or 8, characterized in that, The grain pile cooling mode also includes humidity control inside the storage area, the specific operation of which is as follows: In response to the start command of the grain pile cooling mode, the humidity inside the warehouse is obtained; Humidification, dehumidification, or no humidity treatment is performed based on the obtained humidity inside the warehouse and the preset humidity threshold until the humidity inside the warehouse reaches and is maintained within the preset humidity threshold range. Specifically, the humidification process includes: In response to the humidification signal, the humidifier in the grain cooling unit is activated; During the humidification process, the fan speed of the internal fan is adjusted to the set maximum value, and the operating frequency of the compressor is gradually reduced at intervals of each detection cycle. Continue humidification and frequency adjustment until the frequency adjustment stops when any of the following conditions are met: (1) The current detected evaporator coil temperature is higher than the dew point temperature determined based on the relative humidity collected in the chamber in the previous detection cycle; (2) The operating frequency of the compressor has been reduced to the set minimum value; The dehumidification process specifically includes: In response to the dehumidification signal, the dehumidification module is activated; Get the current airflow speed of the internal fan; Based on the obtained current internal fan speed and the minimum set internal fan speed, the internal fan speed is adjusted to the set minimum value or zero for operation.

10. A grain silo cooling control method according to claim 9, characterized in that, The dew point temperature corresponding to the relative humidity is calculated according to the following formula: Wherein, Td is the dew point temperature (°C); Ta is the return air temperature inside the warehouse (°C); RH is the relative humidity; A and B are both empirical coefficients, and A=17.625, B=243.

04.

11. A grain silo cooling control method according to claim 6, characterized in that, The grain surface cooling mode includes the regulation of grain pile temperature and humidity inside the storage area. The specific operation for regulating the grain pile temperature is as follows: In response to the start command for the grain surface cooling mode, the following steps are executed: Close the second regulating valve, the third regulating valve, and the exhaust valve, and open the first regulating valve and the fourth regulating valve; Simultaneously start the internal fan, compressor and external fan in the grain cooling unit, and set the internal fan to operate at the set maximum wind speed; The return air temperature inside the grain silo and the evaporator coil temperature of the grain cooling unit are obtained. The wind speed of the internal fan is dynamically adjusted based on the return air temperature inside the warehouse and the evaporator coil temperature, so that the grain surface temperature reaches and is maintained within the preset grain surface temperature threshold.

12. A grain silo cooling control method according to claim 6, characterized in that, The mechanical ventilation mode includes adjusting the ventilation status, the specific operation of which is as follows: In response to the command to activate mechanical ventilation mode, the following steps are performed: Close the first and fourth regulating valves, and open the second, third, and exhaust valves; At the same time, the internal fan in the grain cooling unit is started to operate at the set maximum wind speed or the wind speed value input by the user.

13. A grain silo cooling control method according to claim 12, characterized in that, The mechanical ventilation mode also includes humidity control within the warehouse, the specific operation of which is as follows: The humidity inside the chamber is obtained in response to the start command of the mechanical ventilation mode; Humidification, dehumidification, or no humidity treatment is performed based on the obtained humidity inside the chamber and the preset humidity threshold until the humidity inside the chamber reaches and is maintained within the preset humidity threshold range.

14. A grain silo cooling control method according to claim 6, characterized in that, The internal circulation mode includes the adjustment of the ventilation state, the specific operation of which is as follows: In response to the start command for the grain surface cooling mode, the following steps are executed: Close the second regulating valve, the third regulating valve, and the exhaust valve, and open the first regulating valve and the fourth regulating valve; At the same time, the internal fan in the grain cooling unit is started to operate at the set maximum wind speed or the wind speed value input by the user.

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