Method for controlling moisture discharge of a dryer and dryer

Abstract

The present application relates to the technical field of drying, and particularly provides a drying machine moisture removal control method and a drying machine, aiming to solve the problem that when the existing drying machine is in a low ambient temperature during moisture removal, the external tobacco leaves frequently switch between a high temperature and a low temperature, affecting the baking quality; and when the ambient temperature is high, the internal tobacco leaves are in a high humidity while the external tobacco leaves are in a low temperature, which may cause the internal tobacco leaves to rot for a long time. To this end, the moisture removal control method comprises: obtaining the wet-bulb temperature T2 in the drying room of the drying machine; comparing the wet-bulb temperature T2 with the current program set wet-bulb temperature value T5; in the case of T2>T5, obtaining the external environment temperature Tao outside the drying machine; and according to the size of the external environment temperature Tao, controlling the drying machine to enter different moisture removal modes. When moisture removal is performed, the drying machine can enter different moisture removal modes according to the size of the external environment temperature, reducing the temperature fluctuation in the drying room, thereby improving the baking quality.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of drying, and particularly provides a drying machine and a drying machine exhaust control method. BACKGROUND

[0002] In the tobacco drying process, when the exhaust is needed, the heating system is usually in the default closed state, and only the dry-bulb and wet-bulb temperatures in the curing barn are collected by the dry-bulb and wet-bulb sensors inside the curing barn. Due to the serious obstruction of the sensors by tobacco leaves, the hysteresis of temperature and humidity regulation is amplified. Taking the dry-bulb temperature as an example, when the exhaust is started at the 48° dry-bulb curing stage, the sensor inside the tobacco leaves detects that the dry-bulb temperature is 45°, while the dry-bulb temperature of the external tobacco leaves may be only 42° or even lower. At this time, according to the curing system logic, when the sensor detects that the dry-bulb temperature is 43°, the temperature is turned on, at this time, the temperature of the external tobacco leaves is lower than 40°; similarly, during the temperature rising process, the dry-bulb temperature of the external tobacco leaves will be higher than the dry-bulb temperature detected by the sensor inside the tobacco leaves.

[0003] During the exhaust process, when the ambient temperature is low, the external tobacco leaves will frequently switch between high and low temperatures, affecting the curing quality; when the ambient temperature is high, the internal tobacco leaves will be in high humidity for a long time, and the external tobacco leaves will be in low temperature for a long time, which will cause the internal tobacco leaves to rot and the external tobacco leaves to be covered with dust.

[0004] Therefore, the present application needs to provide a new drying machine exhaust control method and drying machine to solve the above technical problems. SUMMARY

[0005] The present application aims to solve the above technical problems, i.e., to solve the problem that in the existing drying machine, during the exhaust process, when the ambient temperature is low, the external tobacco leaves will frequently switch between high and low temperatures, affecting the curing quality; when the ambient temperature is high, the internal tobacco leaves will be in high humidity for a long time, and the external tobacco leaves will be in low temperature for a long time, which will cause the internal tobacco leaves to rot and the external tobacco leaves to be covered with dust.

[0006] To this end, in a first aspect, the present application provides a drying machine exhaust control method, which comprises:

[0007] obtaining the wet-bulb temperature T2 in the curing barn of the drying machine;

[0008] comparing the wet-bulb temperature T2 with the current program set wet-bulb temperature value T5;

[0009] in the case of T2>T5, obtaining the external environment temperature Tao outside the drying machine;

[0010] controlling the drying machine to enter different exhaust modes according to the size of the external environment temperature Tao.

[0011] In the specific embodiment of the moisture exhaust control method of the drying machine, the step of "controlling the drying machine to enter different moisture exhaust modes according to the size of the external environment temperature Tao" specifically comprises:

[0012] comparing the size of the external environment temperature Tao with the first preset temperature Ty1 and the second preset temperature Ty2;

[0013] if Tao≤Ty1, controlling the drying machine to enter a low-temperature moisture exhaust mode;

[0014] if Ty1

[0015] if Tao>Ty2, controlling the drying machine to enter a high-temperature moisture exhaust mode.

[0016] In the specific embodiment of the moisture exhaust control method of the drying machine, the heating chamber of the drying machine is provided with an air outlet, air in the heating chamber enters the curing room through the air outlet, the drying machine comprises a fresh air outlet, a moisture exhaust outlet, a return air outlet, a heat pump heater and an electric heater, and the heat pump heater and the electric heater can heat air in the heating chamber;

[0017] The moisture exhaust control method further comprises:

[0018] when the drying machine enters the low-temperature moisture exhaust mode, controlling the return air outlet to be in an open state;

[0019] the specific operation steps of the low-temperature moisture exhaust mode are:

[0020] obtaining the dry-bulb temperature T1 in the curing room;

[0021] obtaining the dry-bulb temperature T3 of the air outlet of the heating chamber;

[0022] comparing the size of the dry-bulb temperature T1 with the dry-bulb temperature T3;

[0023] if T1-Tcha1≤T3

[0024] if T3

[0025] if T1

[0026] If T3>T1+Tcha1, the heat pump heater and the electric heater are both controlled to be turned off, and the fresh air inlet and the exhaust air outlet are controlled to be in the full open gear;

[0027] wherein Tcha1 is a preset difference temperature.

[0028] In the specific embodiment of the exhaust air control method of the drying machine, an air outlet is arranged on a heating chamber of the drying machine, air in the heating chamber enters a curing barn through the air outlet, the drying machine comprises a fresh air inlet, an exhaust air outlet, a return air inlet, a heat pump heater and an electric heater, and the heat pump heater and the electric heater can heat air in the heating chamber.

[0029] The exhaust air control method further comprises:

[0030] controlling the drying machine to enter a high-temperature exhaust air mode while controlling the fresh air inlet and the exhaust air outlet to be in the full open gear;

[0031] The specific operation steps of the high-temperature exhaust air mode are:

[0032] obtaining a dry-bulb temperature T1 in the curing barn;

[0033] obtaining a dry-bulb temperature T3 and a wet-bulb temperature T4 of the air outlet of the heating chamber;

[0034] obtaining a wet-bulb temperature T5 set in a current program;

[0035] comparing the dry-bulb temperature T3 with the dry-bulb temperature T1;

[0036] comparing the wet-bulb temperature T4 with the wet-bulb temperature T5;

[0037] comparing the wet-bulb temperature T5 with a wet-bulb temperature T2;

[0038] based on the comparison result of the dry-bulb temperature T3 and the dry-bulb temperature T1, selectively controlling the start and stop of the heat pump heater and the electric heater;

[0039] based on the comparison result of the wet-bulb temperature T4 and the wet-bulb temperature T5 and the comparison result of the wet-bulb temperature T5 and the wet-bulb temperature T2, selectively controlling the opening or closing of the return air inlet of the drying machine.

[0040] In the specific embodiment of the exhaust air control method of the drying machine, the step of "based on the comparison result of the dry-bulb temperature T3 and the dry-bulb temperature T1, selectively controlling the start and stop of the heat pump heater and the electric heater" specifically comprises:

[0041] If T1-Tcha2≤T3≤T1, the heat pump heater is controlled to be turned on, and the electric heater is controlled to be turned off;

[0042] If T3 < T1-Tcha2, control the heat pump heater and the electric heater to be both turned on.

[0043] If T1 < T3 < T1+Tcha2, control the heat pump heater to be turned on and the electric heater to be turned off.

[0044] If T3 ≥ T1+Tcha2, control the heat pump heater and the electric heater to be both turned off.

[0045] Wherein, Tcha2 is a preset temperature difference.

[0046] In the specific embodiment of the above method for controlling the dehumidification of the dryer, the step of "selectively controlling the return air inlet of the dryer to be opened or closed based on the comparison results of the wet-bulb temperature T4 and the wet-bulb temperature T5 and the comparison results of the wet-bulb temperature T5 and the wet-bulb temperature T2" specifically includes:

[0047] If T4 < T5-Tcha3, control the return air inlet to be opened.

[0048] If T4 ≥ T5-Tcha3, control the return air inlet to be closed.

[0049] If T5 < T2+Tcha4 and the maintenance time exceeds the set time, control the return air inlet to be closed.

[0050] If T5 ≥ T2+Tcha4, control the return air inlet to be opened.

[0051] Wherein, the opening permission of the return air inlet is higher than the closing permission of the return air inlet, and Tcha3 and Tcha4 are both preset temperature differences.

[0052] In the specific embodiment of the above method for controlling the dehumidification of the dryer, the dryer is provided with a dehumidification heat exchange mechanism, and the air flowing into the dryer from the fresh air inlet of the dryer exchanges heat with the air discharged from the dehumidification outlet of the dryer before entering the heating chamber of the dryer.

[0053] In the specific embodiment of the above method for controlling the dehumidification of the dryer, the specific operation steps of the normal-temperature dehumidification mode are as follows:

[0054] Control the fresh air inlet and the dehumidification outlet of the dryer to be in the full-open gear.

[0055] Control the heat pump heater and the electric heater to be turned off.

[0056] In the specific embodiment of the above method for controlling the dehumidification of the dryer, if the wet-bulb temperature T2 ≤ T5-Tcha5, control the dryer to exit the dehumidification mode.

[0057] wherein Tcha5 is a preset temperature difference.

[0058] In a second aspect, the present application also provides a drying machine comprising a controller configured to perform the drying machine exhaust control method according to any one of the above technical solutions.

[0059] In the case of adopting the above technical solution, the present application can select different drying machine exhaust modes according to the size of the external environment temperature when performing exhaust, adopt a low-temperature exhaust mode when the external environment temperature is low, and adopt a high-temperature exhaust mode when the external environment temperature is high. Different exhaust modes are adopted under different external environments, which can reduce the temperature fluctuation in the drying room, is conducive to improving the drying quality, and avoids the frequent switching of the external tobacco between high and low temperatures when the external environment temperature is low, which affects the drying quality. When the external environment temperature is high, the internal tobacco is in high humidity for a long time, and the external tobacco is in low temperature for a long time, which can cause the internal tobacco to rot and the external tobacco to be covered with dust. BRIEF DESCRIPTION OF DRAWINGS

[0060] The preferred embodiments of the present application will be described below with reference to the accompanying drawings, in which:

[0061] Figure 1 is the main step flow chart of the drying machine exhaust control method provided by the present application;

[0062] Figure 2 is the detailed step flow chart of the drying machine exhaust control method provided by the present application;

[0063] Figure 3 is the main step flow chart of the low-temperature exhaust mode;

[0064] Figure 4 is the main step flow chart of the high-temperature exhaust mode. DETAILED DESCRIPTION

[0065] The preferred embodiments of the present application will be described below with reference to the accompanying drawings, in which:

[0066] It should be noted that in the description of the present application, the terms indicating the direction or positional relationship such as "upper", "lower", "inner", "outer" and the like are based on the direction or positional relationship shown in the drawings, which is merely for the convenience of description, and does not indicate or imply that the related devices or elements must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the ordinal numbers "first", "second" and the like are only for the purpose of description and cannot be understood as indicating or implying relative importance.

[0067] In addition, it should be further pointed out that in the description of the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting" should be understood broadly, for example, it can be fixed connection, or detachable connection or integral connection, it can be mechanical connection, or electrical connection, it can be direct connection, or indirect connection through intermediate medium. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0068] The existing dryer is in a closed state by default when discharging moisture. When the external environment is at low temperature, the external tobacco leaves will frequently switch between high and low temperatures, affecting the baking quality. When the external environment temperature is at high temperature, the internal tobacco leaves will be in high humidity for a long time, and the external tobacco leaves will be at low temperature for a long time, which will cause the internal tobacco leaves to rot and the external tobacco leaves to be covered with dust.

[0069] To solve the above technical problems, the present application provides a dryer, which is provided with an air outlet on the heating chamber. The air in the heating chamber enters the curing barn through the air outlet. Dry and wet bulbs and dry and wet bulb temperature sensors for detecting the temperature of the dry and wet bulbs are installed at the air outlet. The dryer includes a fresh air inlet, a moisture discharge port, an air return port, a heat pump heater and an electric heater. Both the heat pump heater and the electric heater can heat the air in the heating chamber. The air return port is arranged between the curing barn and the heating chamber of the dryer. An air return port cover plate is installed on the air return port to open or close the air return port. The heating chamber is provided with a fresh air inlet. The heat pump heater includes a compressor, an inner heat exchanger and an outer heat exchanger. The inner heat exchanger is equivalent to a condenser, and the outer heat exchanger is equivalent to an evaporator. The electric heater is installed above the inner heat exchanger in the heating chamber.

[0070] Furthermore, the dryer is provided with a moisture discharge and heat exchange mechanism. The air flowing into the dryer from the fresh air inlet exchanges heat with the air discharged from the moisture discharge port through the moisture discharge and heat exchange mechanism, and then enters the heating chamber of the dryer. The high-temperature and high-humidity air discharged from the moisture discharge port is used to heat the air entering the fresh air inlet. The heated air enters the curing barn through the heating chamber, which helps to reduce the speed of reducing the dry bulb temperature in the curing barn. The moisture discharge and heat exchange mechanism can be installed on the side wall of the dryer.

[0071] It should be noted that the structure and working principle of the heat pump heater, the dehumidification heat exchange mechanism and the electric heater are known common knowledge to those skilled in the art, and thus will not be described in detail here.

[0072] Referring to Figure 1 The present application also provides a dehumidification control method of a drying machine, which comprises:

[0073] S1, obtaining a wet bulb temperature T2 in a drying room of the drying machine;

[0074] S2, comparing the wet bulb temperature T2 with a current program set wet bulb temperature value T5;

[0075] S3, in the case of T2>T5, obtaining an external environment temperature Tao outside the drying machine;

[0076] S4, controlling the drying machine to enter different dehumidification modes according to the size of the external environment temperature Tao.

[0077] Specifically, referring to Figure 2 The step S4 of "controlling the drying machine to enter different dehumidification modes according to the size of the external environment temperature Tao" specifically comprises:

[0078] S41, if Tao≤Ty1, controlling the drying machine to enter a low-temperature dehumidification mode;

[0079] S42, if Ty1

[0080] S43, if Tao> Ty2, controlling the drying machine to enter a high-temperature dehumidification mode.

[0081] It should be noted that the values of the first preset temperature and the second preset temperature are determined according to the drying quality of the tobacco leaves in the dehumidification process and whether the phenomenon of rotting or dust sticking occurs, and exemplarily, the first preset temperature is 15℃ and the second preset temperature is 25℃.

[0082] In the above embodiment, when Tao≤Ty1, it indicates that the external environment temperature is low, and the drying machine is in a low-temperature environment, and the temperature of the air entering from the fresh air inlet is low in the dehumidification process, so that the temperature in the drying room is also low, which is easy to make the dry bulb temperature in the drying room fail to reach the set value for a long time. In order to improve the drying quality, a low-temperature dehumidification mode for the low-temperature external environment is designed, which is beneficial to ensure the drying quality. When Tao> Ty2, it indicates that the drying machine is dehumidified in a high-temperature external environment, and at this time, due to the high external environment temperature and high air humidity, the wet bulb temperature is easy to be reduced to the current program set value without dehumidification for a long time, and thus a high-temperature dehumidification mode is specially designed for the high-temperature external environment, which is beneficial to ensure the drying quality.

[0083] In one embodiment, referring to Figure 3 The dehumidification control method further comprises:

[0084] When the drying machine enters the low-temperature dehumidification mode, the return air outlet is controlled to be in an open state;

[0085] The specific operation steps of the low-temperature dehumidification mode are:

[0086] S411, obtaining the dry-bulb temperature T1 in the curing barn;

[0087] S412, obtaining the dry-bulb temperature T3 of the air outlet of the heating chamber;

[0088] S413, comparing the dry-bulb temperature T1 with the dry-bulb temperature T3;

[0089] S414, if T1-Tcha1≤T3

[0090] In the above step, the dry-bulb temperature of the air outlet is less than the dry-bulb temperature in the curing barn, which indicates that the air temperature in the heating chamber is relatively low, and the air needs to be heated to avoid the phenomenon that the dry-bulb temperature in the curing barn drops too fast; and since the external environment temperature is in a low-temperature state, the air temperature entering from the fresh air outlet is low, so the fresh air outlet and the dehumidification outlet are in a half-open gear, which prolongs the dehumidification time, avoids a large amount of low-temperature air entering the heating chamber and then entering the curing barn to affect the temperature in the curing barn, and reduces the temperature fluctuation in the curing barn.

[0091] S415, if T3

[0092] In the above step, T3

[0093] S416, if T1

[0094] In the above steps, the dry-bulb temperature of the air outlet is higher than the dry-bulb temperature in the curing room, but the difference is small, at this time, only need to ensure that the heat pump heater is in the open state, because the temperature in the heating chamber is higher than the temperature in the curing room, the new air outlet is fully opened, which will not make the temperature in the curing room drop too fast, at the same time, in order to improve the dehumidification efficiency, the new air outlet and the dehumidification outlet are fully opened.

[0095] S417, if T3>T1+Tcha1, control the heat pump heater and the electric heater to be closed, and control the new air outlet and the dehumidification outlet to be in the full opening gear;

[0096] In the above steps, because the temperature in the heating chamber is quite different from the temperature in the curing room, and the air temperature of the air outlet is higher than the temperature in the curing room, the new air outlet is fully opened, which will not make the temperature in the curing room drop too fast, and in order to ensure the temperature in the curing room, the heat pump heater is stopped.

[0097] Wherein, Tcha1 is a preset difference temperature.

[0098] It should be noted that without departing from the basic principles of the present application, the present application does not make specific limitation on the value of Tcha1, which is determined according to the drying process requirements of the dryer, for example, Tcha1 is 10℃.

[0099] Regarding steps S411 and S412, it should be noted that although the present application describes that S411 is executed first and S412 is executed later, this is only an example, and those skilled in the art can adjust the execution order of S411 and S412 as needed without departing from the basic principles of the present application, for example, S412 is executed first and S411 is executed later, or both are executed at the same time, the scheme after adjustment belongs to the equivalent technical scheme of the technical scheme described in the present application, and therefore it will also fall within the protection scope of the present application.

[0100] In one embodiment, the dehumidification control method further comprises: controlling the dryer to enter a high-temperature dehumidification mode while controlling the new air outlet and the dehumidification outlet to be in the full opening gear. Because of the high external environment and high air humidity, the wet-bulb temperature is likely to drop to the current program set wet-bulb temperature for a long time, so the return air outlet needs to be opened, and the new air outlet and the dehumidification outlet are in the full opening state.

[0101] In one embodiment, referring to Figure 4 , the specific operation steps of the high-temperature dehumidification mode are:

[0102] S431, obtaining the dry-bulb temperature T1 in the curing room;

[0103] S432, obtaining the dry-bulb temperature T3 and the wet-bulb temperature T4 of the air outlet of the heating chamber;

[0104] S433, acquiring a current program set wet bulb temperature T5;

[0105] S434, comparing the dry bulb temperature T3 with the dry bulb temperature T1;

[0106] S435, comparing the wet bulb temperature T4 with the wet bulb temperature T5;

[0107] S436, comparing the wet bulb temperature T5 with the wet bulb temperature T2;

[0108] S437, selectively controlling the start and stop of the heat pump heater and the electric heater based on the comparison result of the dry bulb temperature T3 and the dry bulb temperature T1;

[0109] S438, selectively controlling the opening or closing of the return air inlet of the dryer based on the comparison result of the wet bulb temperature T4 and the wet bulb temperature T5 and the comparison result of the wet bulb temperature T5 and the wet bulb temperature T2.

[0110] As to steps S431, S432 and S433, it should be noted that although the present application describes that S431 is performed first, then S432, and then S433, this is only an example, and those skilled in the art can adjust the execution order of S431, S432 and S433 as needed without deviating from the basic principles of the present application, for example, S432 is performed first, then S431 and S433, or the three are performed simultaneously, the adjusted scheme belongs to an equivalent technical scheme of the technical scheme described in the present application, and therefore will also fall within the protection scope of the present application.

[0111] As to steps S434, S435 and S436, it should be noted that although the present application describes that S434 is performed first, then S435, and then S436, this is only an example, and those skilled in the art can adjust the execution order of S435, S434 and S436 as needed without deviating from the basic principles of the present application, for example, S435 is performed first, then S434 and S436, or the three are performed simultaneously, the adjusted scheme belongs to an equivalent technical scheme of the technical scheme described in the present application, and therefore will also fall within the protection scope of the present application.

[0112] In one embodiment, the step of "selectively controlling the start and stop of the heat pump heater and the electric heater based on the comparison result of the dry bulb temperature T3 and the dry bulb temperature T1" specifically includes:

[0113] If T1-Tcha2≤T3≤T1, the heat pump heater is controlled to be turned on and the electric heater is controlled to be turned off;

[0114] In the above step, the dry-bulb temperature of the air outlet is less than the dry-bulb temperature in the curing room, which indicates that the air temperature in the heating chamber is relatively low, and the air needs to be heated to avoid the phenomenon that the air entering the curing room makes the dry-bulb temperature drop too fast and the temperature fluctuates greatly.

[0115] If T3 < T1-Tcha2, the heat pump heater and the electric heater are both controlled to be turned on.

[0116] In the above step, T3 < T1-Tcha2, which indicates that the temperature difference between the heating chamber and the curing room is relatively large, the temperature in the heating chamber is low, and the electric heater needs to be turned on to assist the heat pump heater to speed up the temperature rise in the heating chamber, so as to avoid the temperature in the curing room from dropping too fast and affecting the roasting quality.

[0117] If T1 < T3 < T1+Tcha2, the heat pump heater is controlled to be turned on and the electric heater is controlled to be turned off.

[0118] In the above step, the dry-bulb temperature of the air outlet is higher than the dry-bulb temperature in the curing room, but the difference is not large, and at this time, only the heat pump heater needs to be turned on.

[0119] If T3 ≥ T1+Tcha2, the heat pump heater and the electric heater are both controlled to be turned off.

[0120] In the above step, since the temperature in the heating chamber and the temperature in the curing room are relatively large, and the air temperature of the air outlet is higher than the temperature in the curing room, and in order to ensure the temperature in the curing room, the heat pump heater is stopped.

[0121] Tcha2 is a preset temperature difference.

[0122] It should be noted that, without departing from the basic principles of the present application, the present application does not specifically limit the value of Tcha2, which is determined according to the requirements of the drying machine roasting process, for example, Tcha1 is 10℃.

[0123] In one embodiment, the step S438 of "selectively controlling the return air outlet of the drying machine to be opened or closed based on the comparison results of the wet-bulb temperature T4 and the wet-bulb temperature T5 and the comparison results of the wet-bulb temperature T5 and the wet-bulb temperature T2" specifically includes:

[0124] If T4 < T5-Tcha3, the return air outlet is controlled to be opened.

[0125] In the above step, since the wet-bulb temperature of the air outlet is less than the wet-bulb temperature set in the current program, it indicates that the humidity of the air entering the curing room from the air outlet does not affect the decrease of the wet-bulb temperature in the curing room, and in order to reduce the temperature fluctuation in the curing room, the return air outlet is opened.

[0126] If T4≥T5-Tcha3, the return air inlet is controlled to be closed.

[0127] In the above step, since the difference between the wet bulb temperature of the air outlet and the wet bulb temperature set by the current program is small, the wet bulb temperature is easily reduced to the wet bulb temperature set by the current program in the dehumidification process. Therefore, the return air inlet is closed to achieve direct progress and direct discharge, which is beneficial to reduce the wet bulb temperature in the drying room in a short time and ensure the quality of the tobacco.

[0128] If T5<T2+Tcha4, and the maintenance time exceeds the set time, the return air inlet is controlled to be closed.

[0129] In the above step, the wet bulb temperature in the drying room is greater than the wet bulb temperature set by the current program, which indicates that the humidity in the drying room is large and still cannot be reduced within the set dehumidification execution time. At this time, the return air inlet is closed to achieve direct discharge and direct progress, which is beneficial to quickly reduce the wet bulb temperature and ensure the quality of the tobacco.

[0130] If T5≥T2+Tcha4, the return air inlet is controlled to be opened.

[0131] The opening permission of the return air inlet is higher than the closing permission of the return air inlet, and Tcha3 and Tcha4 are both preset temperature difference values.

[0132] In one embodiment, the specific operation steps of the normal temperature dehumidification mode are as follows:

[0133] The fresh air inlet and the dehumidification port of the dryer are controlled to be in the full open gear.

[0134] The heat pump heater and the electric heater are controlled to be closed.

[0135] During the dehumidification process, if the wet bulb temperature T2≤T5-Tcha5, the dryer is controlled to exit the dehumidification mode, wherein Tcha5 is a preset temperature difference value.

[0136] It should be noted that the values of Tcha3, Tcha4 and Tcha5 are not limited in the present application without deviating from the basic principles of the present application, and are determined according to the drying process requirements of the dryer, such as the value of Tcha3 being 5℃, the value of Tcha4 being 2℃, and the value of Tcha5 being 0.5℃.

[0137] In addition, the present application also provides a dryer comprising a controller configured to execute the dehumidification control method of the dryer according to any one of the above technical solutions.

[0138] In the above-mentioned embodiments and various extended embodiments, when the moisture is removed, the present application can select different moisture removal modes of the drying machine according to the size of the external environment temperature. When the external environment temperature is low, the low-temperature moisture removal mode is adopted; when the external environment temperature is high, the high-temperature moisture removal mode is adopted. Different moisture removal modes are adopted under different external environments, which can reduce the temperature fluctuation in the curing room, is conducive to improving the curing quality, and avoids that when the external environment temperature is low, the external tobacco leaves are frequently switched between high and low temperatures, which affects the curing quality; when the external environment temperature is high, the internal tobacco leaves are in high humidity for a long time, and the external tobacco leaves are in low temperature for a long time, which can cause the internal tobacco leaves to rot and the external tobacco leaves to be covered with dust.

[0139] So far, the technical solutions of the present application have been described in combination with the preferred embodiments shown in the drawings, but those skilled in the art can easily understand that the protection scope of the present application is obviously not limited to these specific embodiments. Those skilled in the art can make equivalent changes or replacements to the related technical features without departing from the principles of the present application, and the technical solutions after the changes or replacements will fall within the protection scope of the present application.

Claims

1. A moisture discharging control method of a dryer, characterized by, The moisture removal control method comprises: obtaining a wet bulb temperature T2 in the drying room of the dryer; comparing the wet bulb temperature T2 with a current program setting wet bulb temperature value T5; in the case of T2>T5, obtaining an external environment temperature Tao outside the dryer; controlling the dryer to enter different moisture removal modes according to the size of the external environment temperature Tao; the step of "controlling the dryer to enter different moisture removal modes according to the size of the external environment temperature Tao" specifically comprises: comparing the external environment temperature Tao with a second preset temperature Ty2; if Tao>Ty2, controlling the dryer to enter a high-temperature moisture removal mode; the dryer comprises a return air inlet, a fresh air inlet and a moisture removal port; the moisture removal control method further comprises: controlling the fresh air inlet and the moisture removal port to be in a full opening gear while controlling the dryer to enter the high-temperature moisture removal mode; the specific operation steps of the high-temperature moisture removal mode are: obtaining a wet bulb temperature T4 of an air outlet of the heating chamber; obtaining a current program setting wet bulb temperature T5; comparing the wet bulb temperature T4 with the wet bulb temperature T5; comparing the wet bulb temperature T5 with the wet bulb temperature T2; based on the comparison results of the wet bulb temperature T4 with the wet bulb temperature T5 and the comparison results of the wet bulb temperature T5 with the wet bulb temperature T2, selectively controlling the return air inlet of the dryer to be opened or closed.

2. The moisture discharging control method of a dryer according to claim 1, characterized in that, the step of "controlling the dryer to enter different moisture removal modes according to the size of the external environment temperature Tao" specifically comprises: comparing the external environment temperature Tao with a first preset temperature Ty1; if Tao≤Ty1, controlling the dryer to enter a low-temperature moisture removal mode; if Ty1 3. The moisture discharging control method of a dryer according to claim 2, characterized in that, the heating chamber of the dryer is provided with an air outlet, air in the heating chamber enters the drying room through the air outlet, and the dryer further comprises a heat pump type heater and an electric heater; the heat pump type heater and the electric heater can heat air in the heating chamber; the moisture removal control method further comprises: controlling the return air inlet to be in an open state when the dryer enters the low-temperature moisture removal mode; the specific operation steps of the low-temperature moisture removal mode are: obtaining a dry bulb temperature T1 in the drying room; obtaining a dry bulb temperature T3 of the air outlet of the heating chamber; comparing the dry bulb temperature T1 with the dry bulb temperature T3; if T1-Tcha1≤T3 if T3 if T1 if T3>T1+Tcha1, controlling the heat pump type heater and the electric heater to be both closed, and controlling the fresh air inlet and the moisture removal port to be in a full opening gear; Wherein, Tcha1 is a preset temperature difference.

4. The moisture discharging control method of a dryer according to claim 2, characterized in that, The heating chamber of the drying machine is provided with an air outlet, air in the heating chamber enters the curing barn through the air outlet, the drying machine further comprises a heat pump heater and an electric heater, and the heat pump heater and the electric heater can heat the air in the heating chamber. The specific operation steps of the high-temperature dehumidification mode are further: Obtain the dry-bulb temperature T1 in the curing barn; Obtain the dry-bulb temperature T3 of the air outlet of the heating chamber; Compare the dry-bulb temperature T3 with the dry-bulb temperature T1; Based on the comparison result of the dry-bulb temperature T3 and the dry-bulb temperature T1, selectively control the start and stop of the heat pump heater and the electric heater.

5. The moisture discharging control method of a dryer according to claim 4, characterized in that, The step of "based on the comparison result of the dry-bulb temperature T3 and the dry-bulb temperature T1, selectively control the start and stop of the heat pump heater and the electric heater" specifically includes: If T1-Tcha2≤T3≤T1, control the heat pump heater to start and the electric heater to stop; If T3<T1-Tcha2, control the heat pump heater and the electric heater to start; If T1<T3<T1+Tcha2, control the heat pump heater to start and the electric heater to stop; If T3≥T1+Tcha2, control the heat pump heater and the electric heater to stop; Wherein, Tcha2 is a preset temperature difference.

6. The moisture discharging control method of a dryer according to claim 4, characterized in that, The step of "based on the comparison result of the dry-bulb temperature T3 and the dry-bulb temperature T1, selectively control the start and stop of the heat pump heater and the electric heater" specifically includes: If T4<T5-Tcha3, control the return air outlet to open; If T4≥T5-Tcha3, control the return air outlet to close; If T5<T2+Tcha4, and the maintenance time exceeds the set time, control the return air outlet to close; If T5≥T2+Tcha4, control the return air outlet to open; Wherein, the opening permission of the return air outlet is higher than the closing permission of the return air outlet, and Tcha3 and Tcha4 are both preset temperature differences.

7. The moisture discharging control method of a dryer according to claim 1, characterized in that, The drying machine is provided with a dehumidification and heat exchange mechanism, and the air flowing into the drying machine from the fresh air inlet of the drying machine exchanges heat with the air discharged from the dehumidification port through the dehumidification and heat exchange mechanism before entering the heating chamber of the drying machine.

8. The moisture discharging control method of a dryer according to claim 4, characterized in that, The specific operation steps of the normal-temperature dehumidification mode are: Control the fresh air inlet and the dehumidification port of the drying machine to be in the full-open gear; Control the heat pump heater and the electric heater to be closed.

9. The moisture discharging control method of a dryer according to any one of claims 1-8, characterized in that, If the wet-bulb temperature T2≤T5-Tcha5, control the drying machine to exit the dehumidification mode; Wherein, Tcha5 is a preset temperature difference.

10. A dryer comprising a controller, characterized in that, The controller is configured to be capable of performing the dehumidification control method of the drying machine according to any one of claims 1-9.

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